Reactivity?

Group 2 metals that react with cold water

Calcium (Ca), Strontium (Sr), and Barium (Ba) react with cold water. Magnesium (Mg) reacts only with steam.

Does magnesium react with cold water?

No, magnesium reacts only with steam (hot water vapor), not with cold water.

Group 7 halogen that can displace other halide ions

Chlorine (Cl₂) can displace bromide (Br⁻) and iodide (I⁻) ions from solution.

Can bromine (Br₂) displace chloride (Cl⁻) ions?

No, bromine is less reactive than chlorine, so it cannot displace chloride ions.

Metals that react with dilute acids to produce hydrogen gas

Metals above hydrogen in the reactivity series, e.g., magnesium (Mg), zinc (Zn), iron (Fe).

Does copper react with dilute hydrochloric acid?

No, copper is below hydrogen in the reactivity series and does not react with dilute HCl.

Metals that react with water to produce hydroxides and hydrogen

Potassium (K), sodium (Na), lithium (Li), calcium (Ca), strontium (Sr), and barium (Ba).

Can tertiary alcohols be oxidised by acidified potassium dichromate?

No, tertiary alcohols do not oxidise under these conditions.

Can primary alcohols be oxidised to aldehydes?

Yes, primary alcohols can be oxidised to aldehydes using acidified potassium dichromate.

Precipitate formed when adding NaOH to Fe²⁺ ions

A green precipitate of Fe(OH)₂ forms.

Precipitate formed when adding NaOH to Fe³⁺ ions

A brown precipitate of Fe(OH)₃ forms.

Does CO₂ react with limewater?

Yes, CO₂ turns limewater cloudy due to the formation of CaCO₃.

Does hydrogen gas react with limewater?

No, hydrogen gas does not react with limewater.

What happens when chlorine gas is added to cold, dilute sodium hydroxide solution?

Chlorine disproportionates to form chloride ions and chlorate(I) ions (Cl⁻ and ClO⁻).

Example of a disproportionation reaction in the halogens

Chlorine in cold dilute NaOH: Cl₂ + 2OH⁻ → Cl⁻ + ClO⁻ + H₂O.